200gr maker rex expanding blackout with imr 4227

Discussion about rifles in 300 AAC BLACKOUT (7.62x35mm), hosted by the creator of the cartridge.

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Brody760
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200gr maker rex expanding blackout with imr 4227

Post by Brody760 »

hello ive been looking for a while and cant find many posted loads for a 10.5in 1-8 twist ar pistol the load im looking for consists of converted lc brass cc#41 primers imr 4227 powder and 200gr maker rex expanding blackout bullets. also in a separate question i have a good idea of where to start but any loads with the same components listed but using 208 eldm’s are appreciated. thanks in advance for any answers feel free to post your loads if you happen to use a different primer as i am just looking to get as much info as i can
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bangbangping
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Re: 200gr maker rex expanding blackout with imr 4227

Post by bangbangping »

Welcome. No idea what your reloading experience is so don't be offended by the advice. Couple of things...

1. The limited capacity of the 300 BLK case means you have to be extremely careful in translating loads from one bullet to another. The amount of bullet in the case is what matters, not necessarily the OAL, so you need to know the lengths of the bullets. With some loads it's possible for a seating depth change of 0.1" to take a load from safe to blow-your-gun-up pressure levels.

2. Nobody has a sub load that is perfect for you, even with all the same components and the same barrel. Too many variables. You'll have to work up a load that works for you.

All that said, with the 200 Maker, 10 grains of 4227 loaded from 2.1" to mag length is safe and will put you in the ball park. You have a chronograph, right?
Brody760
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Re: 200gr maker rex expanding blackout with imr 4227

Post by Brody760 »

hey bangbangping i am well aware to not copy loads and expect them to even work at all as i really am just trying to see data on a bunch of peoples loads so i know where to be thanks for telling me the nice way, much appreciated. and about the chrono i do have a competition electronics prochrono dlx. also thanks for the suggested load!
dpete
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Re: 200gr maker rex expanding blackout with imr 4227

Post by dpete »

Here you go, straight off my recipe list:
200 Maker HP – LC case, 8.4 gr IMR 4227, CCI 400 primer, 2.120 COAL, 1.740 CBTO @ 1.026 BBTO, case trimmed to 1.358”

Gets me 970-980 fps which my 8" supressed barrel likes and it will touch holes at 50 yards. YMMV
Brody760
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Re: 200gr maker rex expanding blackout with imr 4227

Post by Brody760 »

awesome thanks for the info!
Brody760
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Posts: 15
Joined: Wed Sep 28, 2022 9:52 pm

Re: 200gr maker rex expanding blackout with imr 4227

Post by Brody760 »

bangbangping wrote: Thu Sep 29, 2022 11:43 am Welcome. No idea what your reloading experience is so don't be offended by the advice. Couple of things...

1. The limited capacity of the 300 BLK case means you have to be extremely careful in translating loads from one bullet to another. The amount of bullet in the case is what matters, not necessarily the OAL, so you need to know the lengths of the bullets. With some loads it's possible for a seating depth change of 0.1" to take a load from safe to blow-your-gun-up pressure levels.

2. Nobody has a sub load that is perfect for you, even with all the same components and the same barrel. Too many variables. You'll have to work up a load that works for you.

All that said, with the 200 Maker, 10 grains of 4227 loaded from 2.1" to mag length is safe and will put you in the ball park. You have a chronograph, right?
looking back i just tried to load my first rex tonight the recommended 2.1 coal is definitely compressed with 9.7grs of 4227.

to get the same compression i get with my 208gr eldms i need a coal of about 2.12 -2.13

At these coal’s itd still be safe to shoot as long as they have the same compression as my 208gr eldm loads right because im making them longer not shorter? and if i do need them a bit longer is there anything to look for such as degraded accuracy with a longer coal?

**fyi i am not trying to use the same load for different bullets i understand thats not how that works im just making sure the listed specs are safe if you happen to have any experience with them.
dpete
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Re: 200gr maker rex expanding blackout with imr 4227

Post by dpete »

What velocity are you getting with that 9.7 grains? Thats the other thing to worry about. You want an accurate load that stays subsonic at all temperatures.
Brody760
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Re: 200gr maker rex expanding blackout with imr 4227

Post by Brody760 »

dpete wrote: Mon Nov 07, 2022 9:02 pm What velocity are you getting with that 9.7 grains? Thats the other thing to worry about. You want an accurate load that stays subsonic at all temperatures.
i have since done some load development and settled on 9.4gr and if i can remember it shoots right at 1010fps
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